Recently, display units with use of an organic electroluminescence (EL) device (organic EL displays) have been increasingly developed. The display units are roughly classified into top surface emission (top emission) display units and bottom surface emission (bottom emission) display units.
In the top surface emission display unit, an upper electrode (e.g., cathode) on light extraction side is typically configured by a transparent electrically conductive film such as indium-tin oxide (ITO), thus causing resistance (cathode resistance) to be high. As a result, a voltage is dropped (occurrence of so-called voltage drop) at a middle portion of a panel, causing an increase in power consumption as well as deterioration of image quality. In this case, use of metal for the upper electrode enables the resistance to be lowered; however, metal has poor light-transmissivity. Thus, the use of metal for the upper electrode reduces light extraction efficiency, causing luminance to be lowered.
In addition, in order to lower the cathode resistance, a method may be adopted in which the transparent electrically conductive film is provided immediately on the organic electroluminescence device. However, the transparent electrically conductive film typically has a high resistance value in a thin film, and thus may desirably have increased thickness in order to lower the resistance value. When the transparent electrically conductive film has increased thickness, however, the light-transmissivity is lowered, leading to lowered luminance. As described, it is not easy for the upper electrode to both achieve light-transmissivity and electrical conductivity.
Furthermore, in order to improve the light extraction efficiency for enhancement of luminance, there has been proposed a device structure with use of a so-called anode reflector (e.g., PTL 1). More specifically, a structure body having such a sloped plane as to surround a pixel aperture is formed with use of a material having a predetermined refraction index.